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Diffstat (limited to 'nptl/tpp.c')
| -rw-r--r-- | nptl/tpp.c | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/nptl/tpp.c b/nptl/tpp.c deleted file mode 100644 index 57eb026088..0000000000 --- a/nptl/tpp.c +++ /dev/null @@ -1,195 +0,0 @@ -/* Thread Priority Protect helpers. - Copyright (C) 2006-2017 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Jakub Jelinek <jakub@redhat.com>, 2006. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#include <assert.h> -#include <atomic.h> -#include <errno.h> -#include <pthreadP.h> -#include <sched.h> -#include <stdlib.h> -#include <atomic.h> - - -int __sched_fifo_min_prio = -1; -int __sched_fifo_max_prio = -1; - -/* We only want to initialize __sched_fifo_min_prio and __sched_fifo_max_prio - once. The standard solution would be similar to pthread_once, but then - readers would need to use an acquire fence. In this specific case, - initialization is comprised of just idempotent writes to two variables - that have an initial value of -1. Therefore, we can treat each variable as - a separate, at-least-once initialized value. This enables using just - relaxed MO loads and stores, but requires that consumers check for - initialization of each value that is to be used; see - __pthread_tpp_change_priority for an example. - */ -void -__init_sched_fifo_prio (void) -{ - atomic_store_relaxed (&__sched_fifo_max_prio, - sched_get_priority_max (SCHED_FIFO)); - atomic_store_relaxed (&__sched_fifo_min_prio, - sched_get_priority_min (SCHED_FIFO)); -} - -int -__pthread_tpp_change_priority (int previous_prio, int new_prio) -{ - struct pthread *self = THREAD_SELF; - struct priority_protection_data *tpp = THREAD_GETMEM (self, tpp); - int fifo_min_prio = atomic_load_relaxed (&__sched_fifo_min_prio); - int fifo_max_prio = atomic_load_relaxed (&__sched_fifo_max_prio); - - if (tpp == NULL) - { - /* See __init_sched_fifo_prio. We need both the min and max prio, - so need to check both, and run initialization if either one is - not initialized. The memory model's write-read coherence rule - makes this work. */ - if (fifo_min_prio == -1 || fifo_max_prio == -1) - { - __init_sched_fifo_prio (); - fifo_min_prio = atomic_load_relaxed (&__sched_fifo_min_prio); - fifo_max_prio = atomic_load_relaxed (&__sched_fifo_max_prio); - } - - size_t size = sizeof *tpp; - size += (fifo_max_prio - fifo_min_prio + 1) - * sizeof (tpp->priomap[0]); - tpp = calloc (size, 1); - if (tpp == NULL) - return ENOMEM; - tpp->priomax = fifo_min_prio - 1; - THREAD_SETMEM (self, tpp, tpp); - } - - assert (new_prio == -1 - || (new_prio >= fifo_min_prio - && new_prio <= fifo_max_prio)); - assert (previous_prio == -1 - || (previous_prio >= fifo_min_prio - && previous_prio <= fifo_max_prio)); - - int priomax = tpp->priomax; - int newpriomax = priomax; - if (new_prio != -1) - { - if (tpp->priomap[new_prio - fifo_min_prio] + 1 == 0) - return EAGAIN; - ++tpp->priomap[new_prio - fifo_min_prio]; - if (new_prio > priomax) - newpriomax = new_prio; - } - - if (previous_prio != -1) - { - if (--tpp->priomap[previous_prio - fifo_min_prio] == 0 - && priomax == previous_prio - && previous_prio > new_prio) - { - int i; - for (i = previous_prio - 1; i >= fifo_min_prio; --i) - if (tpp->priomap[i - fifo_min_prio]) - break; - newpriomax = i; - } - } - - if (priomax == newpriomax) - return 0; - - /* See CREATE THREAD NOTES in nptl/pthread_create.c. */ - lll_lock (self->lock, LLL_PRIVATE); - - tpp->priomax = newpriomax; - - int result = 0; - - if ((self->flags & ATTR_FLAG_SCHED_SET) == 0) - { - if (__sched_getparam (self->tid, &self->schedparam) != 0) - result = errno; - else - self->flags |= ATTR_FLAG_SCHED_SET; - } - - if ((self->flags & ATTR_FLAG_POLICY_SET) == 0) - { - self->schedpolicy = __sched_getscheduler (self->tid); - if (self->schedpolicy == -1) - result = errno; - else - self->flags |= ATTR_FLAG_POLICY_SET; - } - - if (result == 0) - { - struct sched_param sp = self->schedparam; - if (sp.sched_priority < newpriomax || sp.sched_priority < priomax) - { - if (sp.sched_priority < newpriomax) - sp.sched_priority = newpriomax; - - if (__sched_setscheduler (self->tid, self->schedpolicy, &sp) < 0) - result = errno; - } - } - - lll_unlock (self->lock, LLL_PRIVATE); - - return result; -} - -int -__pthread_current_priority (void) -{ - struct pthread *self = THREAD_SELF; - if ((self->flags & (ATTR_FLAG_POLICY_SET | ATTR_FLAG_SCHED_SET)) - == (ATTR_FLAG_POLICY_SET | ATTR_FLAG_SCHED_SET)) - return self->schedparam.sched_priority; - - int result = 0; - - /* See CREATE THREAD NOTES in nptl/pthread_create.c. */ - lll_lock (self->lock, LLL_PRIVATE); - - if ((self->flags & ATTR_FLAG_SCHED_SET) == 0) - { - if (__sched_getparam (self->tid, &self->schedparam) != 0) - result = -1; - else - self->flags |= ATTR_FLAG_SCHED_SET; - } - - if ((self->flags & ATTR_FLAG_POLICY_SET) == 0) - { - self->schedpolicy = __sched_getscheduler (self->tid); - if (self->schedpolicy == -1) - result = -1; - else - self->flags |= ATTR_FLAG_POLICY_SET; - } - - if (result != -1) - result = self->schedparam.sched_priority; - - lll_unlock (self->lock, LLL_PRIVATE); - - return result; -} |